A "Turbulent" day at Aldinga

[Coop]

A “Turbulent” Day at Aldinga

 

Up to today the smallest conventional aircraft I had ever flown (this obviously doesn’t include a brief interlude with hang gliders when I was at uni) was the Grunau Baby II glider, with an empty weight of about 170kg and a max weight of 250 kg. It’s max speed was set at 65kts, somewhat slower than the 80kts usually mentioned in the Grunua’s specifications- perhaps due allowance was being made for its age!! It also had a heavily curved wing section and an unbelievably slow stalling speed around 15 knots!! I remember this well, because during the landing, it felt like I could have got out and walked!

 

This weekend, tho’, I got to fly an even smaller machine, with a lower max weight, even though it has an engine. I got to fly a Druine Turbulent. It was 19-0908, the first home-built aircraft to fly in Australia (previously VH-PWH). It was built in Sydney by Peter Hodgen in 1957-58. It is now owned by Martin Smith of Adelaide Biplanes at Aldinga, and he was gracious enough to allow me to do a few circuits.

 

This machine is a mere 5.3M long, with a wing span of only 6.5M, an empty weight of about 160kg and a Max weight of about 280kg. Standing next to it, it looks like an overgrown model- although these days, there are even R/C models almost this large! One unusual feature is the presence of leading edge slots in the wing ahead of the ailerons.

 

This machine was originally equipped with a converted VW engine of about 45hp, but was subsequently fitted with a 1600 Jabiru of 65hp, and recently a 2200 Jabiru of about 85hp. Given it now has an engine twice as powerful as the original specification, it’s performance is sparkling, to put it mildly!!

 

My first concern was whether I’d be able to fit into it- and it was a bit tight, but since you can get full rudder travel with only ankle movement, and the throttle wasn’t obstructed by my left knee, it was OK. The fuel tap on this machine was directly in front at the bottom of the panel and the gauge- a wire on the end of a float- pokes straight up through the fuel cap in front of your eyes, so there’s no excuse for running out of fuel.

 

 

Starting is easy- turn on the fuel, pull the choke, turn on both magnetos, push the starter, and away she goes. My instructor held the beastie back while I did this, as you need three hands to do all this and hold the handbrake on. With the engine ticking over the machine will gently roll forward unless the brake is used. It is a simple lever on the LHS and operates both brakes via cables. I was told this system needs to be used judiciously as several Turblents have gone over on their backs because their pilots braked too enthusiastically, and the machine is very light in the tail.

 

Taxiing was easy- the steerable tailwheel providing plenty of control and the turning circle is quite small. However I avoided some softer sections of the airfield as the tailwheel is tiny and the main gear are also relatively small.

 

Takeoff was a bit of a blur. As is my usual practice, I opened the throttle slowly and gently, fiddling with the rudder somewhat as I fish-tailed down the runway (it’s quite sensitive), but before the throttle was much more than half open, we’d left the ground. A quick glance at the ASI showed speed rapidly approaching 55kts so I hauled the stick back and kept opening the throttle- and hauled the stick back some more as the speed rapidly went past 65 knots.

 

[ame]

 

[/ame]On the next circuit I lined up on 03 (there being virtually no wind) and had a much better view of proceedings. The little machine squeaked onto the tarmac and I found I needed to be very careful on the rudder as merely thinking about moving your foot is enough to send the machine off to the side. After about 50 metres or so I figured I had it under control, so opened the throttle all the way and leapt into the air again. I had circuit height before I’d reached the end of the runway! Yee-hah!!

 

 

After landing I taxied back for a few photos and then reluctantly headed back to the hangar. After shut-down I wriggled my way out of the cockpit with a grin on my face that will probably last all week. I can see why so many of the early homebuilders selected this as their fun machine. But with its extreme responsiveness and twitchy controls, I bet there were some heart-stopping moments in their first few flights!!

 

Coop

 

 

[siznaudin]

Crikey, Coop ... what a rocket!

 

Great account, as ever - but it's a wonder your head didn't split in two, what with that mile-wide grin.

 

So there's an engine upgrade coming to the Auster to match the performance?

 

Maybe a Merlin or Allison, ex war surplus?

 

BTW - what's the level fight max speed then?

 

 

[Coop]

Crikey, Coop ... what a rocket!Great account, as ever - but it's a wonder your head didn't split in two, what with that mile-wide grin.

So there's an engine upgrade coming to the Auster to match the performance?

 

Maybe a Merlin or Allison, ex war surplus?

 

BTW - what's the level fight max speed then?

Vne is 110 knots. Only got it up to 100 knots during this flight- you really feel like you are moving (and you are!). The airflow around the cockpit gets a bit fierce.

 

How fast you go in level flight depends upon how much of the engine power you use. I only had it to about 85 knots in level flight- dunno how much throttle was left- wasn't paying attention, but it can probably reach its Vne in level flight (or nearly so).

 

No, no plans to upgrade Dorothy- her sedate performance and low stalling speed are very relaxing.... :-)

 

Coop

 

 

[sixtiesrelic]

I took thissy of it in 1962 at Archerfield.

 

It was the first home built I'd ever seen.

 

Got the girlfriend to give it a cuddle to show how tiny it was. The smallest aircraft we'd seen at that time was a Cessna 150

 

 

 

[Coop]

I took thissy of it in 1962 at Archerfield. It was the first home built I'd ever seen.

Got the girlfriend to give it a cuddle to show how tiny it was. The smallest aircraft we'd seen at that time was a Cessna 150

 

Thanks, Sixties. I'll post this link to the folks who own it now- dunno if they have images from its history.

Looks like the undercarriage got changed some time during its history- now sports a simple spring steel system.

 

Regards

 

Coop

 

 

[Guest Darren Masters]

Look at the climb on that little machine! Thanks for sharing

 

 

[Guest David C]

I've always had a soft spot for the Turbulent , ever since seeing them in the UK . They used to feature in some numbers particularly at flyins . The Tiger Club based at Redhill in Surrey had quite a few in the ranks . Thanks for sharing , it was quite a nostalgic trip for me .

 

Dave C

 

 

[Coop]

G'Day Dave and Darren,

 

Happy to oblige- glad you got some enjoyment from it. I certainly did!

 

I'm off the the UK in a week's time, and may look in to Redhill, and will keep an eye out for these little beasties,

 

Regards

 

Coop